The emergence of various technologies has given rise to a need for wearable displays. For example, virtual and augmented reality environments, wireless networks, miniaturization of electronic devices, and mobile computing devices, such as personal digital assistants (PDAs) and mobile telephones, have created a need for wearable displays with which device users can interface and, in at least some cases, carry with them as they move from place to place.
Head-worn displays, often referred to as head-mounted displays (HMDs), have existed for many years. Generally speaking, those HMDs have not been commercially adopted due to one or more of their size, bulk, complexity, or expense. Given the drawbacks of existing HMD designs, there is an interest in developing eyeglass-based display devices that have the general form factor of eyeglasses and that can be worn in similar manner to conventional eyeglasses or sunglasses. Such eyeglass-based display devices would be less obtrusive than previous HMDs and more portable.
There are several challenges to developing an eyeglass-based display device that is likely to be adopted by the public. Successful designs will combine relatively light weight, compactness, and desirable aesthetics. Although achieving a design that combines those attributes is itself difficult, even more difficult is providing those attributes while also delivering acceptable image quality.